Flowmeter



Aug. 3, 1943. c, F. scHoRN FLowMETER Filed March 21, 1942 Patented Aug.,3, o 1943 UNITED STATES PATENT ol-FICE 2,325,884 FLowME'rEn carl F.'sonom, notroit, Mion. l Apolioation Maron 21, 1942*, serial no. 435,612

2 claims. (ci. rsf-209) -Tno object-of this invention is to obtain afuer iiowmeter which willindicate uniformly for increments of flow. Manyflowmeters now in use give an accurate reading for high rates ofiiow anda very approximate reading for low rates of iiow, the reason being thatthe resistance to the ow of fuel'varies as the square of the velocityand therefore, any flowmeter dependent on this property gives largereadings for the higher rates of flow and low readings for the lowerrates of now. The object of this invention is, therefore, to secureuniform divisions on4 the scale. A

'lhe drawing illustrates the novel features of my invention.

In the iigure, I is the fuel entrancewhich directs the ow against theannular disc I which forms the end of`a sleeve I2). The annulardisc I|forms an obstruction to the fuel iiow and engages with a compressionspring I3. If the device is turned 90 into the vertical position and ithe sleeve I2 is made ofy heavy material, the spring I3 may be dispensedwith. In either event, the sleeve I2 slides-freely in a cylinder I4which is contained in a casting I5. 'Ihe cylindrical portion I4 is madeof glass or transparent plastic material. There is an inner tube 23 alsomade of a similar transparent material, preferably a plastic. 'Ihesurface of this inner tube 23 is tapered inwardly so that the distancebetween the inner lip of the annular disc II and the wall of thetaperedtube 23 is increased as the ow increases and asthe disc I I compressesthe spring I3. Fluid then flows to the outlet I6.

An electric bulb I1 is provided with a mirror having a portion I8 in theform of a sphere with the center of the electric bulb I1 as its center.A parabolic portion I9 of the mirror is also provided. The tube 23 issupported by the hollow conical element 20. The inside of the element ispolished so as to reect light. 2| is' a photoelectric cell. Electricityenters the electric bulb I1 through a connection 22.

The electric light bulb I1 obtains its elec'- tricity from the batteryand its intensity is controlled by the rheostat 26. For calibration, thegauge 21 marked MA-milliammeter is\pro vided with a false zero. At zeroiiow some light through the opening 28 is just powerful enough to movethe indicator from the real zero to the false zero.

During the operation of the device, the an-II nular disc II is pushedoverto the rightfbyIthe pressure of the uid flowing in at I0. Thepressure difference between the left and right hand sides of the disc IIis balanced by the spring I3. Hence, if the change in pressure of thespring is ignored, that is, if lthe spring be considered as though it'were infinitely long, the ow would vary as the area between the disc Iand the tube However, the force exerted by the spring increases as it iscompressed. Hence, the flow for a given movement of the disc IIincreases'as the spring I3 is compressed. Hence, more accurate readingsare obtained at the lower rates of iiow than at the higher, exactly thereverse of the readings obtained with an ordinary venturi.

'I'he light rays reflected in the lamp I1 are reiiected by the parabolicsurface I9 into the mouth of the-cone 20 where they emerge into theinterior of the tube 23. The walls of the tube 23 are transparent, sothat the lightemerges through the rtransparent wall I4 yinto thephotoelectric ceu 2| when the vdisc |I is moved over to the right. Bythis means, it is possible to get an accurate indication of the flow offluid ata rate of owbelow that at which the ordinary Verturi meter wouldregister. The greater the opening between the tapered tube 23 and thewall II, the greater the amount of light which falls on thephotoelectric cell 2|?. Hence, the

r vgauge 21 can be calibratedv to read in gallons f tapered wall,yleldable means for moving said adapted to project the light rays.through both sliding cylindrical shield against the ow of uid, a sourceof light adapted to be projected through said casing, reiiectingmeansfor said iight the inner and yioute transparent vwalls when said smo-1dhas been moved by tnfiow or nuid, photoelectric means located outsidelsaid outer transparent wall and adaptedto receive said light that passessaid shield when said shield is moved, andan electric indicatorconnected to said .photoelectric means and adapted to indicate thereonthe amount of light that has passed said shield.

2. A device as set forth in claim 1 in which `there is a small openingin the shield permitting a minimum amount of light to pass through theshield to the photoelectric means when there no flow through theiiowmeter. v

. CARL F. SCHORN.

